What causes Okuma OSP alarm 1120?

External motor 1-8 mechanically overloaded (jam, blockage or binding). Motor running hot from a failing bearing or stuck driven device. Overload relay or heater element on that external motor's starter. Motor winding or wiring fault drawing excessive current.

How do I fix Okuma OSP alarm 1120?

1. Read the code number shown with the alarm: code 1-8 = Number of the external motor whose overload was detected. 2. Read the code to identify which external motor (1-8) tripped, and open the General overload detection monitor referenced by the character-string to confirm the tripped motor. 3. Inspect that external motor and the device it drives (conveyor, pump, fan) for jamming, blockage or binding; clear chips or obstructions with power locked out. 4. Check the motor's overload relay in the cabinet for a trip indication and confirm the heater element matches the motor rating. 5. Reset the overload, restart the motor and measure running current against the nameplate; current still high points to mechanical drag or a failing motor. 6. If the trip repeats with free mechanical movement, lock out power and test the motor windings and starter wiring before replacing the external motor.

Okuma OSP codes

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Okuma OSP Controller

Drive · Intermediate

Alarm 1120

Okuma OSP Alarm A 1120 - Overload detected.

The GENERAL OVERLOAD DETECT function picked up an overload on an external motor; the code 1-8 identifies which external motor tripped. On a parallel 2-spindle machine the object shows the machine system. The affected external motor (conveyor, pump or similar auxiliary) has been shut down by its protector.

Okuma OSPDriveIntermediate

1120

Okuma OSP Alarm A 1120 - Overload detected.

Overload detected.

Common Causes

External motor 1-8 mechanically overloaded (jam, blockage or binding)
Motor running hot from a failing bearing or stuck driven device
Overload relay or heater element on that external motor's starter
Motor winding or wiring fault drawing excessive current

Troubleshooting Steps

1Read the code number shown with the alarm: code 1-8 = Number of the external motor whose overload was detected.
2Read the code to identify which external motor (1-8) tripped, and open the General overload detection monitor referenced by the character-string to confirm the tripped motor.
3Inspect that external motor and the device it drives (conveyor, pump, fan) for jamming, blockage or binding; clear chips or obstructions with power locked out.
4Check the motor's overload relay in the cabinet for a trip indication and confirm the heater element matches the motor rating.
5Reset the overload, restart the motor and measure running current against the nameplate; current still high points to mechanical drag or a failing motor.
6If the trip repeats with free mechanical movement, lock out power and test the motor windings and starter wiring before replacing the external motor.

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